1. Field of the Invention
This invention relates to invalid hoists, the term "invalid" being used herein to include hospital patients and disabled persons generally. It is particularly concerned with hoists comprising an upstanding column from which a lifting arm projects and which is mounted on a base. The lifting arm is raised and lowered by a lifting mechanism within the column and an invalid support member is supported at the end of the arm.
2. Description of Prior Art
Hoists of the foregoing character are known with a manual drive for the lifting mechanism connected to the upper end of a lifting screw of the mechanism at the top of the column. For transport and storage purposes it is desirable that the column should be detachable from the base. In order to provide a power-operated hoist it has been proposed to replace the manual drive at the top of the column by an electric motor unit, a battery by which the motor is energized being mounted on the base. The result is a hoist with a column which is not readily made detachable, partly because of the increased weight of the column which includes the motor unit and also because of the need to provide heavy duty power cables connecting the battery on the chassis to the motor at the top of the column. A further disadvantage is that the motor unit represents additional top weight which should be avoided so far as possible, particularly with a mobile hoist, in the interests of stability.